#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#include<string.h>


int main(int argc,const char* argv[]){
    // if(argc != 2){
    //     return -1;
    // }
    FILE*fp = fopen("./test.txt","w+");
    if(fp == NULL){
        printf("fopen err\n");
        return -1;
    }
    
    fseek(fp,10,SEEK_SET);
    fputc('a',fp);
    fseek(fp,5,SEEK_CUR);
    fputc('b',fp);
    fputc('c',fp);

    long l=ftell(fp);
    printf("%ld\n",l);


    fclose(fp);
    fp=NULL;
    return 0;
}